1. Field of the Invention
The present invention relates to a disk detecting apparatus in a multi-media player in which reproduction can be performed from video disks or digital audio disks of different diameter.
2. Background of the Invention
FIG. 1 is a perspective view showing a carrier for a conventional disk detecting apparatus in an optical disk player which is arranged to be able to play video disks, digital audio disks, or the like, of different diameter. Diagrams of FIGS. 2(a) and (b) explain the disk detecting operation by the carrier.
FIG. 2(a) shows a video disk 1 of 12 inches in diameter, a video disk 2 of 8 inches in diameter, and a digital audio disk 3 of 4.7 inches (hereinafter referred to as "5 inches") in diameter.
The above-mentioned disks are mounted on a carrier 4 which can be horizontally projected from and accommodated into a casing 5. On the carrier 4, there is provided a position restriction edge 6 constituted by a step or projecting portion for guiding an outer circumferential edge of the video disk 1 of 12 inches in diameter so as to mount the disk in a predetermined position. The video disk 1 is mounted on a disk mounting surface 7. Finger-hook recessed portions 8 are formed in the right and left side portions of the carrier 4 so that fingers of the user can be inserted to the lower surface of the outer circumferential portion of the video disk 1 when the video disk 1 is to be moved onto or from the disk mounting surface 7.
A position restriction edge 9 constituted by a step or projecting portion guides an outer circumferential edge of the video disk 2 of 8 inches in diameter so as to mount the video disk 2 in a predetermined position. The video disk 2 is mounted on a disk mounting surface 10. Finger-hook recessed portions 11 are formed in the right and left sides of the position restriction portion 9 so that fingers can be inserted to the lower surface of the outer circumferential portion of the video disk 2 when the video disk 2 is to be moved onto or from the disk mounting surface 11.
A position restriction edge 12 constituted by a step or projecting portion guides the digital audio disk 3 of 5 inches in diameter at its outer circumferential edge portion so as to mount the audio disk 3 in a predetermined position. The digital audio disk 3 is mounted on a disk mounting surface 13. A finger-hook recessed portion 14 is formed in this side of the position restriction portion 12 so that fingers can be inserted to the lower surface of the outer circumferential portion of the audio disk 3 when the digital audio disk 3 is to be moved onto or from the disk mounting surface 13.
Further, all of the above-mentioned circular position restriction portions 6, 8 and 12 are provided coaxially with each other. Holes 15, 16 and 17 are formed respectively in the disk mounting surfaces 13, 7, and 10 so that light radiated from detection means 19, 20 and 21, each constituted by a light emission diode and a photo detector fixed on a substrate 18, is reflected by the disks 1, 2, and 3, and the reflected light can be passed through the respective holes. An opening 22 in the carrier 4 allows movement of a not-shown pickup in a radial direction of the disks and the relative movement of a turntable 24 which will be described later. A driving motor 23 rotates the video disks 1 and 2. A turntable 24 is fixed on the rotary shaft of the motor 23. A clamper 25 clamps the disks.
When the carrier 4 is projected from the casing 5 and any one of the disks 1, 2 and 3 is mounted on the corresponding one of the disk mounting surfaces 7, 10, 13, the disk is guided by the corresponding one of the position restriction edges 6, 9, and 12 so as to be mounted on the corresponding one of the disk mounting surfaces 7, 10, and 13.
Then, the carrier 4 on which the selected one of the disks 1, 2, and 3 has been mounted is moved into the inside of the casing 5 so as to be positioned just above the turntable 24 (FIG. 2(a)). In that state, the carrier 4 is stopped once and the existence of the reflected light of the light emitted from the detection means 19, 20, and 21 is detected through the holes 15, 16, and 17.
All the detection means 19, 20 and 21 receive the reflected light when the largest disk 1 is mounted, both the detection means 19 and 20 receive the reflection light when the medium sized video disk 2 is mounted, and only the detection means 19 receives the reflection light when the smallest digital audio disk 3 is mounted. Thus, the kind of the mounted disk can be detected by the respective output signals from the detection means 19, 20 and 21.
The motor and the turntable to be positioned below the carrier 4 are selected to be the motor 23 and the turntable 24 for a video disk when either one of the video disks 1 and 2 has been mounted while a not-shown motor and a not-shown turntable for a digital audio disk are selected when the digital audio disk 3 has been mounted. After completion of the selection and change-over operation, the carrier 4 is moved downward. As a result, the selected disk is mounted on the corresponding turntable and clamped by the clamper 25. The carrier 4 descends to a position illustrated in FIG. 2(b) in which the carrier 4 does not prevent the disk from rotating and does not contact the detection means 19, 20 and 21. In this position, the carrier 4 stands by.
In the conventional disk detection apparatus, however, it is necessary to provide a plurality of the detection means 19, 20, and 21 corresponding to the kinds of the disks so that the circuit arrangement becomes complicated and raises the cost. Further, it is necessary to form the special holes 15, 16 and 17 in the carrier 4 corresponding to the detection means 19, 20 and 21 which degrade the appearance of the apparatus.